arXiv subjects

Christof Röhrig

Publications and source records attributed to Christof Röhrig.

3 recordsLinked to original sources

arXiv2026

Experimental Evaluation of LPWAN Technologies: mioty, LoRaWAN, Sigfox, NB-IoT, and LTE-M in Deep Indoor Environments

Low Power Wide Area Networks (LPWAN) are often used in applications such as Smart City, Smart Buildings and Smart Metering. Energy meters are often located in underground spaces that are difficult to reach with wireless technology. This paper presents an experimental study comparing different LPWAN technologies in terms of building penetration. The technologies mioty, Low Power Long Range Wide Area Network (LoRaWAN), Sigfox, Narrow Band Internet of Things (NB-IoT), and Long Term Evolution for Machines (LTE-M) are evaluated experimentally. The aim of the research is to investigate the performance of building penetration of different radio technologies in real-life scenarios. The measurements are performed with inexpensive off-the-shelf equipment. The results of the study are integrated in the metering system of the Dortmund University of Applied Sciences and Arts.

cs.NI↗

arXiv2025

LPWAN based IoT Architecture for Distributed Energy Monitoring in Deep Indoor Environments

Continuous energy monitoring is essential for identifying potential savings and predicting the energy requirements of buildings. Energy meters are often located in underground spaces that are difficult to reach with wireless technology. This paper presents an experimental study comparing different Low Power Wide Area Networks (LPWAN) technologies in terms of building penetration and radio coverage. The technologies Low Power Long Range Wide Area Networks (LoRaWAN), Narrow Band Internet of Things (NB-IoT), Sigfox 0G and Wireless Smart Ubiquitous Networks (Wi-SUN) are evaluated experimentally. It also proposes a distributed hybrid IoT architecture that combines multiple LPWAN technologies using an abstraction layer to optimize cost and coverage. Communication is message-based using the publish-subscribe messaging pattern. It is implemented using the MQTT protocol. The abstraction layer decodes the proprietary binary data and converts it to a normalized JSON format.

cs.NI↗

arXiv2025

Aerial Assistance System for Automated Firefighting during Turntable Ladder Operations

Fires in industrial facilities pose special challenges to firefighters, e.g., due to the sheer size and scale of the buildings. The resulting visual obstructions impair firefighting accuracy, further compounded by inaccurate assessments of the fire's location. Such imprecision simultaneously increases the overall damage and prolongs the fire-brigades operation unnecessarily. We propose an automated assistance system for firefighting using a motorized fire monitor on a turntable ladder with aerial support from an unmanned aerial vehicle (UAV). The UAV flies autonomously within an obstacle-free flight funnel derived from geodata, detecting and localizing heat sources. An operator supervises the operation on a handheld controller and selects a fire target in reach. After the selection, the UAV automatically plans and traverses between two triangulation poses for continued fire localization. Simultaneously, our system steers the fire monitor to ensure the water jet reaches the detected heat source. In preliminary tests, our assistance system successfully localized multiple heat sources and directed a water jet towards the fires.

cs.RO↗